#!/bin/bash
#version 0.8
#date 12 Dec 2023
#Copyright Graeme Richards - RaspberryConnect.com
#Released under the GPL3 Licence (https://www.gnu.org/licenses/gpl-3.0.en.html)

#Script to automatically switch to an Access Point when no Wifi connection is available
#Developed on a Raspberry Pi PiOS Bookworm for use with Network Manager

#Additions where made for the Phoniebox project
#https://github.com/MiczFlor/RPi-Jukebox-RFID

#Device Names
wdev0='%WIFI_INTERFACE%' #wifi device that AP will work on

#AP setup
ap_profile_name='%AUTOHOTSPOT_PROFILE%'
ap_ssid='%AUTOHOTSPOT_SSID%'
ap_pw='%AUTOHOTSPOT_PASSWORD%'
ap_ip='%AUTOHOTSPOT_IP%/24'
ap_gate='%IP_WITHOUT_LAST_SEGMENT%.254'

timer_service_name='%AUTOHOTSPOT_TIMER_NAME%'

#If wifi is disabled in Network Manager, then enable it automatically.
#if set to 'false' then wifi will stay off and no AccessPoint will be generated or Network Connection will be available.
re_enable_wifi=false

#If true, check if timer is active. Will have been disabled if arg -a used.
re_enable_timer=false

#*************************************
#*****No user editable lines below****

NO_SSID='NoSSid'

profiles=() #Currently Available Profiles
active="" #The active connection
active_ap=false #is the active profile an AP y/n
nw_profile=() #saved NW Profiles
ap_profile=() #The saved AP profiles
ssidChk=("$NO_SSID")
force_hotspot=false

#Function is NM installed and running
check_prerequisite() {
    if systemctl -all list-unit-files NetworkManager.service | grep "could not be found" >/dev/null 2>&1 ;then
        if systemctl -all list-unit-files dhcpcd.service | grep "(running)" >/dev/null 2>&1 ;then
            echo "This script is not compatible with the network setup."
            echo "Please use the dhcpcd version"
        else
            echo "Network Manager is not managing the Wifi on this device"
            echo "Unable to continue."
        fi
        exit 1
    else
        local isnm="$( systemctl status NetworkManager | grep '(running)' )"
        if echo "$isnm" | grep -v "(running)" ;then  >/dev/null 2>&1; #NM not running
            echo "Network Manager is required but is not the active system network service"
            echo "Unable to continue."
            exit 1
        fi
    fi
}

#Function get all wifi profiles
saved_profiles()
{
    ap_profile=()
    nw_profile=()
    local n="$(nmcli -t -f TYPE,NAME,AUTOCONNECT-PRIORITY con show)" #Capture Output
    n="$(awk 1 ORS=':' <(echo "$n"))" #Replaces LF with : Delimeter
    local profiles=()
    readarray -d ':' -t profiles < <(printf "%s" "$n") #Change to array output
    if [ ! -z "$profiles" ]; then
        for (( c=0; c<=${#profiles[@]}; c+=3 )) #array of profiles
        do
            if [ ! -z "${profiles[$c+1]}" ] ; then
                local conn="$(nmcli con show "${profiles[$c+1]}" | grep 'wireless.mode')" #show mode infurstructure, AP
                local mode=()
                readarray -d ':' -t mode < <(printf "%s" "$conn")
                local mode2="$(echo "${mode[1]}" | sed 's/[[:blank:]]//g')"
                if [ "$mode2" = "ap" ]; then
                    ap_profile+=("${profiles[$c+1]}")
                    echo "AP Profile: ${profiles[$c+1]}"
                elif [ "$mode2" = "infrastructure" ]; then
                    nw_profile+=("${profiles[$c+1]}")
                    echo "NW Profile: ${profiles[$c+1]}"
                fi
            fi
        done
    fi
}

#Function what is the current active wifi
active_wifi()
{
    local act="$(nmcli -t -f TYPE,NAME,DEVICE con show --active | grep "$wdev0")" #List of active devices
    act="$(awk 1 ORS=':' <(echo "$act"))" #Replaces LF with : Delimeter
    local active_name=()
    readarray -d ':' -t active_name < <(printf "%s" "$act") #Change to array output
    if [ ! -z "$active_name" ]; then
        active="${active_name[1]}"
    else
        active=""
    fi
}

#Function is the current Connection an AP
is_active_ap()
{
    active_ap=false
    if [ ! -z "$active" ] ; then
        for i in "${ap_profile[@]}"
        do
            if [[ $i == "$active" ]]; then
                active_ap=true
                break
            fi
        done
    fi
}

#Function IW SSID scan
nearby_ssids_iw()
{
    if [ ${#nw_profile[@]} -eq 0 ]; then #only scan if NW profiles exists#
        return
    fi

    #Check to see what SSID's and MAC addresses are in range
    echo "SSID availability check"
    local i=0; j=0
    while [ $i -eq 0 ]
    do
        local scanreply=$(iw dev "$wdev0" scan ap-force 2>&1)
        local ssidreply=$(echo "$scanreply" | egrep "^BSS|SSID:")
        if [ $j -ge 5 ]; then
            ssidreply=""
            i=1
        elif [ -z "$ssidreply" ] ; then
            echo "Error scan SSID's, try $j: $scanreply"
            j=$((j + 1))
            sleep 2
        else
            #success
            i=1
        fi
    done

    ssidChk=()
    for profile in "${nw_profile[@]}"
    do
        echo "Assessing profile: ${profile}"
        local idssid=$(nmcli -t con show "${profile}" | grep "wireless.ssid")
        if (echo "$ssidreply" | grep -F -- "${idssid:21}" ) >/dev/null 2>&1
        then
            echo "Valid SSID detected, assessing Wifi status"
            ssidChk+="${profile}"
        fi
    done

    if [ "${#ssidChk[@]}" -eq 0 ]; then
        echo "No Valid SSID detected"
        ssidChk+="$NO_SSID"
    fi
}

check_device()
{
    echo "Device availability check"
    local j=0
    while [ true ] #wait for wifi if busy, usb wifi is slower.
    do
        if [ $j -ge 5 ]; then
            echo "No wifi device '$wdev0' connected"
            exit 1
        elif (nmcli device show "$wdev0" 2>&1 >/dev/null) ; then
            echo "Wifi device '$wdev0' available"
            if (rfkill list wifi -rno HARD,SOFT | grep -i "unblocked.*unblocked") >/dev/null 2>&1 ; then
                return
            else
                if [[ $re_enable_wifi = true ]] ; then
                    nmcli radio wifi on
                    echo "Wifi has been re-activated"
                    sleep 10 #delay to allow wifi to initialise
                    return
                else
                    echo "Wifi is deactivated"
                    exit 0
                fi
            fi
        else
            j=$((j + 1))
            sleep 2
        fi
    done
}

#Activate AP profile
start_ap()
{
    local ex=0
    for i in "${ap_profile[@]}"
    do
        if [[ $i == "$ap_profile_name" ]]; then
            ex=1 #known saved AP profile is available
            break
        fi
    done
    if [ $ex -eq 0 ];then
        ap_new_profile #if known AP profile not found, create it
    fi
    nmcli con up "$ap_profile_name" >/dev/null 2>&1
    sleep 3 #give time for ap to be setup
    active_wifi
    is_active_ap
    if [ "$active_ap" = true ]; then
        echo "Access Point started"
        local curip="$(nmcli -t con show $active | grep IP4.ADDRESS)"
        readarray -d ':' -t ipid < <(printf "%s" "$curip")
        local showip="$(echo "${ipid[1]}" | sed 's/[[:blank:]]//g')"
        if [ ! -z $showip ]; then
            echo "AP on IP Address ${showip::-3}"
        fi
    else
        echo "AP failed to be created."
    fi
}

#Activate NW profile
start_nw()
{
    if [ "$active_ap" = true ]; then
        echo "The active profile is $active. Shutting down"
        nmcli con down "$active" >/dev/null 2>&1
    fi

    local active_nw=""
    for i in "${nw_profile[@]}"
    do
        echo "Checking: $i"
        con="$(nmcli con up $i)"
        if ( echo "$con" | grep 'Connection successfully activated' ) >/dev/null 2>&1; then
            echo "Connection was good"
            active_wifi
            active_nw="$active"
        elif ( echo "$con" | grep 'Connection activation failed' ) >/dev/null 2>&1; then
            echo "Unable to make a connection. Check the password is ok for the ssid ${nw_profile[$c]}"
            active_nw=""
        else
            echo "Unable to confirm the connection status"
            active_nw=""
        fi
        if [ ! -z "$active_nw" ] ;then
            echo "A valid connection has been made with $i"
            break
        fi
    done

    if [ -z "$active_nw" ] ;then
        echo "A network connection has not been made with any known ssid. Activating access point"
        start_ap
    fi
}

#Function Create AP profile
ap_new_profile()
{
    echo "Create a AP profile ${ap_profile_name}"
    nmcli device wifi hotspot ifname $wdev0 con-name "$ap_profile_name" ssid "$ap_ssid" band bg password "$ap_pw" >/dev/null 2>&1
    nmcli con mod "$ap_profile_name" ipv4.method shared ipv4.addr "$ap_ip" ipv4.gateway "$ap_gate" >/dev/null 2>&1
    ap_profile+=("$ap_profile_name")
}

#Main
check_prerequisite
check_device

while getopts "aht" opt; do
    case $opt in
        a )
            force_hotspot=true
            ;;
        t )
            re_enable_timer=true
            ;;
        h )
            sc="$(basename $0)"
            echo -e "\nby default the $sc script will setup a connection to a WiFi network where a profile exists"
            echo "otherwise an Access Point called $ap_ssid will be created. Using ip address $ap_ip"
            echo "The local wifi signals will be check every 2 minutes. If a known SSID comes into range"
            echo "the Access Point will be shutdown and a connection to the Wifi network will be made."
            echo "using sudo $sc -a will activate the Access Point regardless of any existing WiFi profile"
            echo "and stop the timed checks. Use sudo $sc to return to normal use."
            exit
            ;;
        * )
            echo "option not valid"
            exit
            ;;
    esac
done

saved_profiles #get list of saved profile
active_wifi
is_active_ap
echo -e "The active profile is $active\n"

if [ "$force_hotspot" = true ]; then
    if [ ! "$active_ap" = true ]; then
        systemctl stop "$timer_service_name"
        start_ap
    elif [ ! "$active" = "$ap_profile_name" ]; then #Other AP is running, swap to this one
        nmcli con down "$active"
        start_ap
    else
        echo "Access Point $active is already running"
    fi
else
    if [ ! -z "$active" ]; then #Active Profile Yes
        if [ "$active_ap" = true ]; then #Yes it's an AP profile
            nearby_ssids_iw #scan for nearby SSID's
            if [ "${ssidChk[0]}" != "$NO_SSID" ]; then #known ssid in range
                start_nw
            elif [ ! "$active" = "$ap_profile_name" ]; then #Other AP is running, swap to this one
                nmcli con down "$active"
                start_ap
            fi
        fi
    else #no active profile
        nearby_ssids_iw #scan for nearby SSID's
        if [ "${ssidChk[0]}" != "$NO_SSID" ]; then #known ssid in range
            start_nw
        else
            start_ap
        fi
    fi

    if [[ $re_enable_timer = true ]] ; then
        #check if timer is active. Will have been disabled if arg -a used.
        tup="$(systemctl list-timers | grep '${timer_service_name}')"
        if [ -z "$tup" ];then
            systemctl start "$timer_service_name"
            echo "Reactivated timer"
        fi
    fi
fi

active_wifi
is_active_ap
echo -e "\nThe Wifi profile in use is: $active"
echo -e "Is this a local access point? $active_ap\n"
